The present invention generally relates to an artificial light source device and more particularly to an artificial light source device in which the light transmitted from a light source lamp is converted into parallel light by means of a parabola reflection mirror, the converted parallel light is guided once into the optical conductor rod, the light discharged from an optical conductor rod is guided into an optical conductor cable comprising a large number of optical fibers, and the light discharged from each optical fiber is used as the light source. In particular, after the parallel light reflected at the parabola reflection mirror passes once through the optical conductor rod; the light is guided into the optical conductor cable in order to guide it effectively and protect the light-receiving edge of the optical conductor cable from being burnt out. Further, the optical conductor cable is prevented from guiding ultraviolet rays.
In general, it might be possible to illuminate any place by the use of an electric lamp. However, illumination in explosive atmosphere or in water may result in danger of explosion or electric leakage. For this reason, an explosion-proof or water-proof electric appliance has to be chosen for use in such a place. However, such explosion-roof and water-proof appliances are voluminous, heavy, and expensive. Further, it is impossible to realize a perfectly explosion-proof or water-proof appliance. The present applicant previously proposed an optical composition reaction device for nuturing chlorella, etc. and a plant cultivation device for promoting cultivation of plants in an atmosphere containing carbon dioxide gas. These devices reuire light for performing optical composition reaction and the light source requires a large number of spotted light sources which do not discharge heat and which are small in size. For the purpose of realizing such light sources, the present applicant previously proposed various methods; that is to say, guiding the light obtained by focussing solar rays with a lens, etc. into an optical conductor cable comprising a large number of optical fibers, guiding the light through the optical conductor cable to an optical composition reaction device for the chlorella nurturing device and the plant-promotion-cultivating device, and so on, and using the light discharged from the optical fiber as the spotted light source. However, if the optical composition reaction device has to perform optical composition reaction even at night, artificial light is used instead of solar rays as an original light source. On that occasion, it might be necessary that the light from the artificial light source be guided into the light conductor cable and further guided to the optical composition reaction device through the optical conductor cable, and both the solar rays and the artificial light are alternatively used by switching them. When occasion demands, both the solar rays and the artificial light sometimes have to be used at the same time.